Informator was the spacecraft component of the planned Koskon medium earth-orbit communications satellite system. A single test launch was made, but funding was not forthcoming, and the planned 45 satellite constellation never materialized.

Informator was developed by the Polyot Scientific Production Association and the Elas Scientific Production Association. The 600-kg satellite was planned to operate in orbits of around 1,000 km at an inclination of 83 degrees. It was cylindrical (diameter 1.8 m, height 4 m) with two solar panels designed to produce 1 kW average power. Informator relied on gravity gradient stabilization and was projected to have an operational lifetime of 5 years or more.

The operational Koskon system was to consist of 32-45 Informator-class satellites with multiple satellites in several orbital planes. Although replacement spacecraft would be launched by the Kosmos booster, the initial groups of three spacecraft were to be deployed using the Zenit launch vehicle. The first operational spacecraft were to be launched early as 1997 with deployments completed by 1998-1999. Uplink (1.656-1.660 GHz) and downlink (1.555-1.559 GHz) communication would be at a rate of 4-5 MBaud, while cross-linked communications at 2.0-2.1 GHz and 0.5 MBaud was advertised. C-band transmissions may also have been possible. The two primary control centers were to be located in the Moscow and Omsk regions. Informator 1 also carried the Soviet RS14 and the German RUDAK 2 amateur satellite transponders as piggy-back payloads.

The single launch of the prototype satellite was not followed by any others.

Length: 4.00 m (13.10 ft). Maximum Diameter: 1.80 m (5.90 ft). Mass: 600 kg (1,320 lb). Electrical System: Solar panels. Electric System: 1.00 average kW.

• 1991 January 29 - Oscar 21 - Program: Oscar. Launch Site: Plesetsk. Launch Complex: LC133/3. Launch Vehicle: Kosmos 3. Mass: 600 kg (1,320 lb). Perigee: 956 km (594 mi). Apogee: 1,008 km (626 mi). Inclination: 82.90 deg. Period: 104.70 min.
  Prototype satellite for the planned Koskon (Space Conversion) Global Space Communication System. It was planned that the Koskon constellation would consist of a constellation of 32 to 45 satellites in 1997-2001. Also carried amateur radio transponders and performed geological research. Routine communications, collection and relaying of information in the interests of the Ministry of Geology of the USSR and other branches of the country's national economy, and the development of communications between amateur radio-operators.